eBook formats

What is the CHM format?

CHM — Compiled HTML Help

CHM is Microsoft Compiled HTML Help: a packed set of HTML pages with an index and search, used for Windows help files and many e-books.

R convert from CHM CHM Converter

Convert CHM to

About the CHM format

CHM files bundle HTML pages, images, a table of contents and a search index. Windows software shipped its manuals this way, and many technical books were distributed as CHM.

Only Windows opens CHM natively, and it often blocks downloaded ones. Converting to PDF or EPUB makes the content readable on any device.

Programs that open CHM

  • Windows HTML Help
  • xCHM
  • Calibre
  • KchmViewer

What CHM is used for

  • Software manuals
  • Technical e-books
  • Windows help files

Other eBook formats

All 17 eBook formats · all supported formats